Zolpidem Tartrate is used with certain other drugs, the effects of
either drug could be increased, decreased, or altered. It is especially
important to check with your doctor before combining Zolpidem Tartrate
with the following:

Zolpidem Tartrate was evaluated in healthy subjects in single-dose
interaction studies for several CNS drugs. Imipramine in combination with
zolpidem produced no pharmacokinetic interaction other than a 20% decrease
in peak levels of imipramine, but there was an additive effect of decreased
alertness. Similarly, chlorpromazine in combination with zolpidem produced
no pharmacokinetic interaction, but there was an additive effect of
decreased alertness and psychomotor performance. A study involving
haloperidol and zolpidem revealed no effect of haloperidol on the
pharmacokinetics or pharmacodynamics of zolpidem.

The lack of a drug interaction following single-dose administration does not
predict a lack following chronic administration.A single-dose interaction
study with zolpidem 10 mg and fluoxetine 20 mg at steady-state levels in
male volunteers did not demonstrate any clinically significant
pharmacokinetic or pharmacodynamic interactions. When multiple doses of
zolpidem and fluoxetine at steady-state concentrations were evaluated in
healthy females, the only significant change was a 17% increase in the
zolpidem half-life. There was no evidence of an additive effect in
psychomotor performance.Following five consecutive nightly doses of zolpidem
10 mg in the presence of sertraline 50 mg (17 consecutive daily doses, at
7:00 am, in healthy female volunteers), zolpidem Cmax was significantly
higher (43%) and Tmax was significantly decreased (53%). Pharmacokinetics of
sertraline and N-desmethylsertraline were unaffected by zolpidem.

Some compounds known to inhibit CYP3A may increase exposure to zolpidem. The
effect of inhibitors of other P450 enzymes has not been carefully evaluated.

A randomized, double-blind, crossover interaction study in ten healthy
volunteers between itraconazole (200 mg once daily for 4 days) and a single
dose of zolpidem (10 mg) given 5 hours after the last dose of itraconazole
resulted in a 34% increase in AUC0-∞ of zolpidem. There were no significant
pharmacodynamic effects of zolpidem on subjective drowsiness, postural sway,
or psychomotor performance.

A randomized, placebo-controlled, crossover interaction study in eight
healthy female subjects between five consecutive daily doses of rifampin
(600 mg) and a single dose of zolpidem (20 mg) given 17 hours after the last
dose of rifampin showed significant reductions of the AUC (-73%), Cmax
(-58%), and T½ (-36%) of zolpidem together with significant reductions in
the pharmacodynamic effects of zolpidem.

A randomized double-blind crossover interaction study in twelve healthy
subjects showed that co-administration of a single 5 mg dose of zolpidem
tartrate with ketoconazole, a potent CYP3A4 inhibitor, given as 200 mg twice
daily for 2 days increased Cmax of zolpidem by a factor of 1.3 and increased
the total AUC of zolpidem by a factor of 1.7 compared to zolpidem alone and
prolonged the elimination half-life by approximately 30% along with an
increase in the pharmacodynamic effects of zolpidem. Caution should be used
when ketoconazole is given with zolpidem and consideration should be given
to using a lower dose of zolpidem when ketoconazole and zolpidem are given
together. Patients should be advised that use of Zolpidem Tartrate
with ketoconazole may enhance the sedative effects.